Lasers are widely use in various fields, including medical applications for soft and hard tissue treatment. Some laser applications often call for transformation of laser energy into acoustical energy. For example, such applications as laser thrombolysis, laser lithotripsy, laser root canal treatment and periodontal pocket debridement utilize laser induced bubble formation, shockwave generation and cavitation. Those applications call for a pulse laser with a selective wavelength which is highly absorbed by chromophores in the tissues, like water or blood. For example, Ho or I'm lasers have a wavelength at which those lasers are highly absorbed by water, so they are widely used for laser lithotripsy to remove impacted stones from the urinary tract by creating bubble and shockwaves that causes fragmentation of the stone (VersaPulse PowerSuite, Lumenis Ltd., Yokneam, Israel).
The Er laser with a wavelength at which that laser is extremely highly absorbed by water is used for treating root canals, root debridement of periodontal pockets, caries removal and other dental applications. For example, Er laser can induce bubbles formed in the water contained in the pulp chamber and root canal (WaterLase, BioLase, Inc., Irvine, Calif., USA; LighWalker, Fotona d.d, Ljubljana, Slovenia, EU). The drawback of those lasers is their high cost that limits their application in various fields, especially in dentistry. The need, therefore, exists to develop a new laser acoustical converter that can be used in various fields at a significantly lower cost.